Renin-inhibiting compounds are known for control of hypertension. Of particular interest herein are compounds useful as renin inhibiting agents.
Renin is a proteolytic enzyme produced and secreted into the bloodstream by the juxtaglomerular cells of the kidney. In the bloodstream, renin cleaves a peptide bond in the serum protein angiotensinogen to produce a decapeptide known as angiotensin I. A second enzyme known as angiotensin converting enzyme, cleaves angiotensin I to produce the octapeptide known as angiotensin II. Angiotensin II is a potent pressor agent responsible for vasoconstriction and elevation of cardiovascular pressure. Attempts have been made to control hypertension by blocking the action of renin or by blocking the formation of angiotensin II in the body with inhibitors of angiotensin I converting enzyme.
Classes of compounds published as inhibitors of the action of renin on angiotensinogen include renin antibodies, pepstatin and its analogs, phospholipids, angiotensinogen analogs, pro-renin related analogs and peptide aldehydes.
A peptide isolated from actinomyces has been reported as an inhibitor of aspartyl proteases such as pepsin, cathepsin D and renin [Umezawa et al, in J. Antibiot. (Tokyo), 23, 259-262 (1970)]. This peptide, known as pepstatin, was found to reduce blood pressure in vivo after the injection of hog renin into nephrectomized rats [Gross et al, Science, 175, 656 (1971)]. Pepstatin has the disadvantages of low solubility and of inhibiting acid proteases in addition to renin. Modified pepstatins have been synthesized in an attempt to increase the specificity for human renin over other physiologically important enzymes. While some degree of specificity has been achieved, this approach has led to rather high molecular weight hepta- and octapeptides [Boger et al, Nature, 303, 81 (1983)]. High molecular weight peptides are generally considered undesirable as drugs because gastrointestinal absorption is impaired and plasma stability is compromised.
Short peptide aldehydes have been reported as renin inhibitors [Kokubu et al, Biochim. Biophys. Res. Commun., 118, 929 (1984); Castro et al, FEBS Lett., 167, 273 (1984)]. Such compounds have a reactive C-terminal aldehyde group and would likely be unstable in vivo.
Other peptidyl compounds have been described as renin inhibitors. EP Appl. #128,762, published Dec. 18, 1984, describes dipeptide and tripeptide glyco-containing compounds as renin inhibitors [also see Hanson et al, Biochm. Biophys. Res. Comm., 132, 155-161 (1985), 146, 959-963 (1987)]. EP Appl. #181,110, published May 14, 1986, describes dipeptide histidine derivatives as renin inhibitors. EP Appl. #186,977 published Jul. 9, 1986 describes renin-inhibiting compounds containing an alkynyl moiety, specifically a propargyl glycine moiety, attached to the main chain between the N-terminus and the C-terminus, such as N-[4(S)-[(N)-[bis(1-naphthylmethyl)acetyl]-DL-propargylglycylamino]-3(S)-hydroxy-6-methylheptanoyl]-L-isoleucinol. EP Appl. #189,203, published Jul. 30, 1986, describes peptidyl-aminodiols as renin inhibitors. EP Appl. #200,406, published Dec. 10, 1986, describes alkylnaphthylmethylpropionyl-histidyl aminohydroxy alkanoates as renin inhibitors. EP Appl. #216,539, published Apr. 1, 1987, describes alkylnaphthylmethylpropionyl aminoacyl aminoalkanoate compounds as renin inhibitors orally administered for treatment of renin-associated hypertension. EP Appl. #229,667, published Jul. 22, 1987, describes acyl xcex1-aminoacyl aminodiol compounds having a piperazinylcarbonyl or an alkylaminoalkylcarbonyl terminal group at the N-amino acid terminus, such as 2(S)-{[(1-piperazinyl)carbonyl]-oxy]-3-phenylpropionyl}-Phe-His amide of 2(S)-amino-1-cyclohexyl-3(R), 4(S)-dihydroxy-6-methylheptane. PCT Application No. WO 87/04349, published Jul. 30, 1987, describes aminocarbonyl aminoacyl hydroxyether derivatives having an alkylamino-containing terminal substituent and which are described as having renin-inhibiting activity for use in treating hypertension. EP Appl. #300,189 published Jan. 25, 1989 describes amino acid monohydric derivatives having an alkylamino-alkylamino N-terminus and a xcex2-alanine-histidine or sarcosyl-histidine attached to the main chain between the N-terminus and the C-terminus, which derivatives are mentioned as useful in treating hypertension. U.S. Pat. No. 4,902,706 which issued Feb. 13, 1990 describes a series of histidineamide-containing amino alkylaminocarbonyl-H-terminal aminodiol derivatives for use as renin inhibitors. U.S. Pat. No. 5,032,577 which issued Jul. 16, 1991 describes a series of histidineamide-aminodiol-containing renin inhibitors.
Ethynyl alanine amino diol compounds, having utility as renin inhibitors for treatment of hypertension in a subject, constitute a family of compounds of general Formula I: 
wherein A is selected from methylene, CO, SO and SO2; wherein X is selected from oxygen atom, methylene and NR10 with R10 selected from hydrido, alkyl and benzyl; wherein each of R1 and R9 is a group independently selected from hydrido, alkyl, cycloalkyl, alkoxyacyl, haloalkyl, alkoxycarbonyl, benzyloxycarbonyl, loweralkanoyl, haloalkylacyl, phenyl, benzyl, naphthyl, and naphthylmethyl, any one of which groups having a substitutable position may be optionally substituted with one or more radicals selected from alkyl, alkoxy, alkenyl, alkynyl, halo, haloalkyl, cyano and phenyl, and wherein the nitrogen atom to which R1 and R9 are attached may be combined with oxygen to form an N-oxide; wherein R2 is selected from hydrido, alkyl, dialkylaminoalkyl, alkylacylaminoalkyl, benzyl and cycloalkyl; wherein R3 is selected from alkyl, cycloalkylalkyl, acylaminoalkyl, phenylalkyl, naphthylmethyl, aryl, heterocyclicalkyl and heterocycliccycloalkyl, wherein the cyclic portion of any of said phenylalkyl, naphthylmethyl, aryl, heterocyclicalkyl and heterocycliccycloalkyl groups may be substituted by one or more radicals selected from halo, hydroxy, alkoxy and alkyl; wherein each of R4 and R6 is independently selected from hydrido, alkyl, benzyl and cycloalkyl; wherein R5 is selected from 
wherein V is selected from hydrido, alkyl, cycloalkyl, haloalkyl, benzyl and phenyl; wherein each of R13 and R14 is a radical independently selected from hydrido, alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, heterocyclic, heterocyclicalkyl and heterocycliccycloalkyl; wherein R7 is selected from substituted or unsubstituted alkyl, cycloalkyl, phenyl, cycloalkylalkyl and phenylalkyl, any one of which may be substituted with one or more groups selected from alkyl, hydroxy, alkoxy, halo, haloalkyl, alkenyl, alkynyl and cyano; wherein R8 is selected from hydrido, alkyl, haloalkyl, alkylcycloalkyl, cycloalkyl, cycloalkylalkyl, hydroxyalkyl, alkenyl, alkylcycloalkenyl and alkoxycarbonyl; wherein each of R11 and R12 is independently selected from hydrido, alkyl, haloalkyl, dialkylamino and phenyl; and wherein m is zero or one; wherein n is a number selected from zero through five; wherein p is a number selected from zero through five; and wherein q is a number selected from zero through five; or a pharmaceutically-acceptable salt thereof.
A preferred family of compounds consists of compounds of Formula I wherein A is selected from methylene, CO, SO and SO2; wherein X is selected from oxygen atom, methylene and NR10 with R10 selected from hydrido, alkyl and benzyl; wherein each of R1 and R9 is independently selected from hydrido, lower alkyl, haloalkyl, cycloalkyl, alkoxycarbonyl, benzyloxycarbonyl, loweralkanoyl, alkoxyacyl, phenyl and benzyl, and wherein the nitrogen atom to which R1 and R9 are attached may be combined with oxygen to form an N-oxide; wherein each of R2, R4 and R6 is independently selected from hydrido and alkyl; wherein R3 is selected from phenylalkyl, naphthylmethyl, cyclohexylalkyl, cyclopentylalkyl, heteroarylalkyl and heteroarylcycloalkyl; wherein R5 is selected from 
wherein V is selected from hydrido, alkyl, haloalkyl, benzyl and phenyl; wherein each of R13 and R14 is a radical independently selected from hydrido, alkyl, alkenyl, alkynyl, cycloalkyl, heteroaryl, heteroarylalkyl and heteroarylcycloalkyl; wherein R7 is selected from substituted or unsubstituted cyclohexylmethyl and benzyl, either one of which may be substituted with one or more groups selected from alkyl, hydroxy, alkoxy, halo and haloalkyl; wherein R8 is selected from hydrido, methyl, ethyl, n-propyl, n-butyl, isobutyl, cycloalkyl, cycloalkylalkyl, hydroxyalkyl, alkenyl, fluoroalkenyl and fluoroalkyl; wherein each of R11 and R12 is independently selected from hydrido, alkyl, dialkylamino and phenyl; wherein m is zero or one; wherein n is a number selected from zero through five; wherein p is a number selected from zero through five; and wherein q is a number selected from zero through five; or a pharmaceutically-acceptable salt thereof.
A more preferred family of compounds consists of compounds of Formula I wherein A is selected from methylene, CO, SO and SO2; wherein X is selected from oxygen atom, methylene and NR10 with R10 selected from hyrido, alkyl and benzyl; wherein each of R1 and R9 is independently selected from hydrido, alkyl, alkoxyacyl, haloalkyl, alkoxycarbonyl, benzyloxycarbonyl, and benzyl, and wherein the nitrogen atom to which R1 and R9 are attached may be combined with oxygen to form an N-oxide; wherein each of R2, R4 and R6 is independently selected from hydrido and alkyl; wherein R3 is selected from benzyl, phenethyl, cyclohexylmethyl, phenpropyl, pyrrolidinyl, piperidinyl, pyrrolidinylmethyl, piperidinylmethyl, pyrazolemethyl, pyrazoleethyl, pyridylmethyl, pyridylethyl, thiazolemethyl, thiazoleethyl, imidazolemethyl, imidazoleethyl, thienylmethyl, thienylethyl, thiazolylcyclopropyl, imidazolecyclopropyl, thienylcyclopropyl, furanylmethyl, furanylethyl, oxazolemethyl, oxazoleethyl, isoxazolemethyl, isoxazoleethyl, pyridazinemethyl, pyridazineethyl, pyrazinemethyl and pyrazineethyl; wherein R5 is selected from 
wherein V is selected from hydrido, alkyl and haloalkyl; wherein each of R13 and R14 is a radical independently selected from hydrido, alkyl, alkenyl, alkynyl, thiazole and thiazolemethyl; wherein R7 is cyclohexylmethyl; wherein R8 is selected from ethyl, n-propyl, isobutyl, cycloalkyl, cycloalkylalkyl, alkenyl, fluoroalkenyl and perfluoropropyl; wherein each of R11 and R12 is independently selected from hydrido, alkyl, dialkylamino and phenyl; wherein m is zero or one; wherein n is a number selected from zero through five; wherein p is a number selected from zero through five; and wherein q is a number selected from zero through five; or a pharmaceutically-acceptable salt thereof.
An even more preferred family of compounds consists of compounds Formula I wherein A is selected from CO and SO2; wherein X is selected from oxygen atom, methylene and NR10 with R10 selected from hydrido and methyl; wherein each of R1 and R9 is independently selected from hydrido, lower alkyl, alkoxyacyl, alkoxycarbonyl, benzyloxycarbonyl, haloalkyl and benzyl, and wherein the nitrogen atom to which R1 and R9 are attached may be combined with oxygen to form an N-oxide; wherein R2 is selected from hydrido, methyl, ethyl and isopropyl; wherein R3 is selected from benzyl, phenethyl, cyclohexylmethyl pyrrolidinyl, piperidinyl, pyrrolidinylmethyl, piperidinylmethyl, pyrazolemethyl, pyrazoleethyl, pyridylmethyl, pyridylethyl, thiazolemethyl, thiazoleethyl, imidazolemethyl, imidazoleethyl, thienylmethyl, thienylethyl, thiazolylcyclopropyl, imidazolecyclopropyl, thienylcyclopropyl, furanylmethyl, furanylethyl, oxazolemethyl, oxazoleethyl, isoxazolemethyl, isoxazoleethyl, pyridazinemethyl, pyridazineethyl, pyrazinemethyl and pyrazineethyl; wherein each of R4 and R6 is independently selected from hydrido and methyl; wherein R5 is selected from 
wherein V is selected from hydrido, alkyl and trifluoromethyl; wherein each of R13 and R14 is a radical independently selected from hydrido, alkyl and alkynyl; wherein R7 is cyclohexylmethyl; wherein R8 is independently selected from ethyl, n-propyl, isobutyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, allyl, vinyl and fluorovinyl; wherein each of R11 and R12 is independently selected from hydrido, alkyl, dialkylamino and phenyl; wherein m is zero; wherein n is a number selected from zero through five; wherein p is a number selected from zero through five; and wherein q is a number selected from zero through five; or a pharmaceutically-acceptable salt thereof.
A highly preferred family of compounds consists of compounds of Formula I wherein A is selected from CO and SO2; wherein X is selected from oxygen atom and methylene; wherein each of R1 and R9 is independently selected from hydrido, methyl, ethyl, n-propyl, isopropyl, benzyl, xcex2,xcex2,xcex2-trifluoroethyl, t-butyloxycarbonyl and methoxymethylcarbonyl, and wherein the nitrogen atom to which R1 and R9 are attached may be combined with oxygen to form an N-oxide; wherein R2 is selected from hydrido, methyl, ethyl and isopropyl; wherein R3 is selected from benzyl, cyclohexylmethyl, phenethyl, pyrazolemethyl, pyrazoleethyl, pyridylmethyl, pyridylethyl, thiazolemethyl, thiazoleethyl, imidazolemethyl, imidazoleethyl, thienylmethyl, thienylethyl, furanylmethyl, furanylethyl, oxazolemethyl, oxazoleethyl, isoxazolemethyl, isoxazoleethyl, pyridazinemethyl, pyridazineethyl, pyrazinemethyl and pyrazineethyl; wherein R5 is selected from 
wherein V is selected from hydrido, alkyl and trifluoromethyl; wherein each of R13 and R14 is a radical independently selected from hydrido, methyl, ethyl, propyl and ethynyl; wherein R7 is cyclohexylmethyl; wherein each of R4 and R6 is independently selected from hydrido and methyl; wherein R8 is selected from ethyl, n-propyl, isobutyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclohexylmethyl, cyclohexylethyl, fluorovinyl, allyl and vinyl; wherein each of R11 and R12 is independently selected from hydrido, alkyl, dialkylamino and phenyl; wherein m is zero; wherein n is a number selected from zero through five; wherein p is a number selected from zero through five; and wherein q is a number selected from zero through five; or a pharmaceutically-acceptable salt thereof.
A more highly preferred class of compounds consists of compounds of Formula I wherein A is selected from CO and SO2; wherein X is selected from oxygen atom and methylene; wherein each of R1 and R9 is a group independently selected from hydrido, methyl, ethyl, n-propyl, isopropyl, benzyl, xcex2,xcex2,xcex2-trifluoroethyl, t-butyloxycarbonyl and methoxymethylcarbonyl, and wherein the nitrogen atom to which R1 and R9 are attached may be combined with oxygen to form an N-oxide; wherein R2 is selected from hydrido, methyl, ethyl and isopropyl; wherein R3 is selected from benzyl, cyclohexylmethyl, phenethyl, imidazolemethyl, pyridylmethyl and 2-pyridylethyl; wherein R5 is selected from 
wherein V is selected from hydrido, alkyl and trifluoromethyl; wherein each of R13 and R14 is a radical independently selected from hydrido, methyl and ethynyl; wherein R7 is cyclohexylmethyl; wherein each of R4 and R6 is independently selected from hydrido and methyl; wherein R8 is selected from ethyl, n-propyl, isobutyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, cyclohexylmethyl, cyclohexylethyl, allyl, vinyl and fluorovinyl; wherein each of R11 and R12 is independently selected from hydrido, alkyl and phenyl; wherein m is zero; wherein n is a number selected from zero through three; wherein p is a number selected from one through three; and wherein q is zero or one; or a pharmaceutically-acceptable salt thereof.
The term xe2x80x9chydridoxe2x80x9d denotes a single hydrogen atom (H). This hydrido group may be attached, for example, to an oxygen atom to form a hydroxyl group; or, as another example, one hydrido group may be attached to a carbon atom to form a NR10 group; or, as another example, two hydrido groups may be attached to a carbon atom to form a xe2x80x94CH2-group. Where the term xe2x80x9calkylxe2x80x9d is used, either alone or within other terms such as xe2x80x9chaloalkylxe2x80x9d and xe2x80x9chydroxyalkylxe2x80x9d, the term xe2x80x9calkylxe2x80x9d embraces linear or branched radicals having one to about twenty carbon atoms or, preferably, one to about twelve carbon atoms. More preferred alkyl radicals are xe2x80x9clower alkylxe2x80x9d radicals having one to about ten carbon atoms. Most preferred are lower alkyl radicals having one to about six carbon atoms. The term xe2x80x9ccycloalkylxe2x80x9d embraces cyclic radicals having three to about ten ring carbon atoms, preferably three to about six carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. The term xe2x80x9chaloalkylxe2x80x9d embraces radicals wherein any one or more of the alkyl carbon atoms is substituted with one or more halo groups, preferably selected from bromo, chloro and fluoro. Specifically embraced by the term xe2x80x9chaloalkylxe2x80x9d are monohaloalkyl, dihaloalkyl and polyhaloalkyl groups. A monohaloalkyl group, for example, may have either a bromo, a chloro, or a fluoro atom within the group. Dihaloalkyl and polyhaloalkyl groups may be substituted with two or more of the same halo groups, or may have a combination of different halo groups. A dihaloalkyl group, for example, may have two fluoro atoms, such as difluoromethyl and difluorobutyl groups, or two chloro atoms, such as a dichloromethyl group, or one fluoro atom and one chloro atom, such as a fluoro-chloromethyl group. Examples of a polyhaloalkyl are trifluoromethyl, 1,1-difluoroethyl, 2,2,2-trifluoroethyl, perfluoroethyl and 2,2,3,3-tetrafluoropropyl groups. The term xe2x80x9cdifluoroalkylxe2x80x9d embraces alkyl groups having two fluoro atoms substituted on any one or two of the alkyl group carbon atoms. The terms xe2x80x9calkylolxe2x80x9d and xe2x80x9chydroxyalkylxe2x80x9d embrace linear or branched alkyl groups having one to about ten carbon atoms any one of which may be substituted with one or more hydroxyl groups. The term xe2x80x9calkenylxe2x80x9d embraces linear or branched radicals having two to about twenty carbon atoms, preferably three to about ten carbon atoms, and containing at least one carbon-carbon double bond, which carbon-carbon double bond may have either cis or trans geometry within the alkenyl moiety. The term xe2x80x9calkynylxe2x80x9d embraces linear or branched radicals having two to about twenty carbon atoms, preferably two to about ten carbon atoms, and containing at least one carbon-carbon triple bond. The term xe2x80x9ccycloalkenylxe2x80x9d embraces cyclic radicals having three to about ten ring carbon atoms including one or more double bonds involving adjacent ring carbons. The terms xe2x80x9calkoxyxe2x80x9d and xe2x80x9calkoxyalkylxe2x80x9d embrace linear or branched oxy-containing radicals each having alkyl portions of one to about ten carbon atoms, such as methoxy group. The term xe2x80x9calkoxyalkylxe2x80x9d also embraces alkyl radicals having two or more alkoxy groups attached to the alkyl radical, that is, to form monoalkoxyalkyl and dialkoxyalkyl groups. The xe2x80x9calkoxyxe2x80x9d or xe2x80x9calkoxyalkylxe2x80x9d radicals may be further substituted with one or more halo atoms, such as fluoro, chloro or bromo, to provide haloalkoxy or haloalkoxyalkyl groups. The term xe2x80x9calkylthioxe2x80x9d embraces radicals containing a linear or branched alkyl group, of one to about ten carbon atoms attached to a divalent sulfur atom, such as a methythio group. Preferred aryl groups are those consisting of one, two, or three benzene rings. The term xe2x80x9carylxe2x80x9d embraces aromatic radicals such as phenyl, naphthyl and biphenyl. The term xe2x80x9caralkylxe2x80x9d embraces aryl-substituted alkyl radicals such as benzyl, diphenylmethyl, triphenyl methyl, phenyl-ethyl, phenylbutyl and diphenylethyl. The terms xe2x80x9cbenzylxe2x80x9d and xe2x80x9cphenylmethylxe2x80x9d are interchangeable. The terms xe2x80x9caryloxyxe2x80x9d and xe2x80x9carylthioxe2x80x9d denote radical respectively, aryl groups having an oxygen or sulfur atom through which the radical is attached to a nucleus, examples of which are phenoxy and phenylthio. The terms xe2x80x9csulfinylxe2x80x9d and xe2x80x9csulfonylxe2x80x9d, whether used alone or linked to other terms, denotes respectively divalent radicals SO and SO2. The term xe2x80x9caralkoxyxe2x80x9d, alone or within another term, embraces an aryl group attached to an alkoxy group to form, for example, benzyloxy. The term xe2x80x9cacylxe2x80x9d whether used alone, or within a term such as acyloxy, denotes a radical provided by the residue after removal of hydroxyl from an organic acid, examples of such radical being acetyl and benzoyl. xe2x80x9cLower alkanoylxe2x80x9d is an example of a more prefered sub-class of acyl. The term xe2x80x9camidoxe2x80x9d denotes a radical consisting of nitrogen atom attached to a carbonyl group, which radical may be further substituted in the manner described herein. The amido radical can be attached to the nucleus of a compound of the invention through the carbonyl moiety or through the nitrogen atom of the amido radical. The term xe2x80x9calkenylalkylxe2x80x9d denotes a radical having a double-bond unsaturation site between two carbons, and which radical may consist of only two carbons or may be further substituted with alkyl groups which may optionally contain additional double-bond unsaturation. The term xe2x80x9cheterocyclicxe2x80x9d, as used alone or within groups such as xe2x80x9cheterocyclicalkylxe2x80x9d, and xe2x80x9cheterocycliccycloalkylxe2x80x9d, (hereinafter referred to as xe2x80x9cheterocyclic-containing groupsxe2x80x9d) embraces radicals having a saturated, or partially unsaturated, or fully saturated heterocyclic group, wherein the cyclic portion consists of a ring system having one ring or two fused rings, which ring system contains one, two or three hetero atoms as ring members selected from nitrogen, oxygen and sulfur, and which ring system has 4 to about 12 ring members. Examples of saturated heterocyclic-containing groups are pyrrolidinyl, piperidinyl, pyrrolidinylmethyl, piperidinylmethyl, pyrrolidinylcyclopropyl and piperidinylcyclopropyl. The term xe2x80x9cheteroarylxe2x80x9d, whether used alone or within the greater terms xe2x80x9cheteroarylalkylxe2x80x9d or xe2x80x9cheteroarylcycloalkylxe2x80x9d, denotes a subset of xe2x80x9cheterocyclic-containing groupsxe2x80x9d having a cyclic portion which is fully-unsaturated, that is, aromatic in character, and which has one or two hetero atoms as ring members, said hetero atoms selected from oxygen, sulfur and nitrogen atoms, and which ring system has five or six ring members. The xe2x80x9cheteroarylxe2x80x9d ring may be attached to a linear or branched alkyl radical having one to about ten carbon atoms or may be attached to a cycloalkyl radical having three to about nine carbon atoms. Examples of such heteroarylalkyl or heteroarylcycloalkyl groups are pyrazolemethyl, pyrazoleethyl, pyridylmethyl, pyridylethyl, thiazolemethyl, thiazoleethyl, imidazolemethyl, imidazoleethyl, thienylmethyl, thienylethyl, furanylmethyl, furanylethyl, oxazolemethyl, oxazoleethyl, thiazolylcyclopropyl, imidazolecyclopropyl, thienylcyclopropyl, isoxazolemethyl, isoxazoleethyl, pyridazinemethyl, pyridazineethyl, pyrazinemethyl and pyrazineethyl. The xe2x80x9cheterocyclicxe2x80x9d portion or xe2x80x9cheteroarylxe2x80x9d portion of the radical, as well as the alkyl or cycloalkyl portion of groups containing a xe2x80x9cheterocyclicxe2x80x9d or xe2x80x9cheteroarylxe2x80x9d portion, may be substituted at a substitutable position with one or more groups selected from oxo, alkyl, alkoxy, halo, haloalkyl, cyano, aralkyl, aralkoxy, aryl and aryloxy. Such xe2x80x9cheterocyclicxe2x80x9d, xe2x80x9cheterocyclicxe2x80x9d-containing group, or xe2x80x9cheteroarylxe2x80x9d group may be attached as a substituent through a carbon atom of the hetero ring system, or may be attached through a carbon atom of a moiety substituted on a hetero ring-member carbon atom, for example, through the methylene substituent of an imidazolemethyl moiety. Also, a heterocyclic or heterocyclic-containing group may be attached through a ring nitrogen atom. For any of the foregoing defined radicals, preferred radicals are those containing from one to about fifteen carbon atoms.
Specific examples of alkyl groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, methylbutyl, dimethylbutyl and neopentyl. Typical alkenyl and alkynyl groups may have one unsaturated bond, such as an allyl group, or may have a plurality of unsaturated bonds, with such plurality of bonds either adjacent, such as allene-type structures, or in conjugation, or separated by several saturated carbons.
Also included in the family of compounds of Formula I are isomeric forms, including diastereoisomers, and the pharmaceutically-acceptable salts thereof. The term xe2x80x9cpharmaceutically-acceptable saltsxe2x80x9d embraces salts commonly used to form alkali metal salts and to form addition salts of free acids or free bases. The nature of the salt is not critical, provided that it is pharmaceutically-acceptable. Suitable pharmaceutically-acceptable acid addition salts of compounds of Formula I may be prepared from an inorganic acid or from an organic acid. Examples of such inorganic acids are hydrochloric, hydrobromic, hydroiodic, nitric, carbonic, sulfuric and phosphoric acid. Appropriate organic acids may be selected from aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, carboxylic and sulfonic classes of organic acids, example of which are formic, acetic, propionic, succinic, glycolic, gluconic, lactic, malic, tartaric, citric, ascorbic, glucuronic, maleic, fumaric, pyruvic, aspartic, glutamic, benzoic, anthranilic, p-hydroxybenzoic, salicyclic, phenylacetic, mandelic, embonic (pamoic), methansulfonic, ethanesulfonic, 2-hydroxyethanesulfonic, pantothenic, benzenesulfonic, toluenesulfonic, sulfanilic, mesylic, cyclohexylaminosulfonic, stearic, algenic, xcex2-hydroxybutyric, malonic, galactaric and galacturonic acid. Suitable pharmaceutically-acceptable base addition salts of compounds of Formula I include metallic salts made from aluminium, calcium, lithium, magnesium, potassium, sodium and zinc or organic salts made from N,Nxe2x80x2-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N-methylglucamine) and procaine. Also included within the phrase xe2x80x9cpharmaceutically-acceptable saltsxe2x80x9d are xe2x80x9cquaternaryxe2x80x9d salts or salts of xe2x80x9coniumxe2x80x9d cations, such as ammonium, morpholinium and piperazinium cations, as well as any substituted derivatives of these cations where the salt is formed on the nitrogen atom lone pair of electrons. All of these salts may be prepared by conventional means from the corresponding compound of Formula I by reacting, for example, the appropriate acid or base with the compound of formula I.
Compounds of Formula I would be useful to inhibit enzymatic conversion of angiotensionogen to angiotensin I. When administered orally, a compound of Formula I would be expected to inhibit plasma renin activity and, consequently, lower blood pressure in a mammalian subject (e.g., a human subject). Thus, compounds of Formula I would be therapeutically useful in methods for treating hypertension by administering to a hypertensive subject a therapeutically-effective amount of a compound of Formula I. The phrase xe2x80x9chypertensive subjectxe2x80x9d means, in this context, a mammalian subject suffering from or afflicted by the effects of hypertension or susceptible to a hypertensive condition if not treated to prevent or control such hypertension.

A suitably protected amino aldehyde 1 is treated with a Grignard reagent or other organometallic reagent, preferably vinylmagnesium bromide, to obtain the vinyl carbinol 2. This material, suitably protected, is oxidized, preferably with ozone, followed by dimethyl sulfide or zinc treatment, to give intermediate 3. The preceeding process is exemplified in Hanson, et al., J. Org. Chem. 50, 5399 (1985). This aldehyde is reacted with an organometallic reagent such as isobutylmagnesium chloride to give intermediate 4. Other suitable organometallic reagents include ethylmagnesium bromide, vinylmagnesium bromide, cyclopropylmagnesium bromide, and allylmagnesium bromide, but the choices are not limited to these reagents. After the formation of 4, further transformation of the added side chain is permitted, before going on the next depicted step. For example, the compound 4 derived from the addition of allylmagnesium bromide may be cyclopropanated via diazomethane and rhodium acetate, to give a cyclopropylmethyl side chain. Compound 4 is deprotected then coupled, using standard amide/peptide coupling methodology to protected triple bond-containing (ethynyl) amino acid derivatives 5 to give compound 6. These standard coupling procedures such as the carbodiimide, active ester (N-hydroxysuccinimide), and mixed carbonic anhydride methods are shown in Benoiton, et al. J. Org. Chem. 48, 2939 (1983) and Bodansky, et al. xe2x80x9cPeptide Synthesisxe2x80x9d, Wiley (1976). Ethynyl-containing amino acid derivatives may be prepared by using procedures such as found in Schollkopf, Tetrahedron 39, 2085 (1983). Intermediate 6 is then deprotected, then coupled to intermediate 7 using the standard amide/peptide coupling methodology, to give compounds of Formula I. Suitable protecting groups may be selected from among those reviewed by R. Geiger in xe2x80x9cThe Peptidesxe2x80x9d, Academic Press, N.Y. vol. 2 (1979). For example, P1 ray by Boc or Cbz; P2 may be a typical oxygen protective group such as acetyl or t-butyldimethylsilyl. 
Intermediate 7 may be prepared according to the schematic of Synthetic Scheme 2. Intermediate 7 is prepared by coupling amine 8 to mono-protected carboxylic acid 9. Carboxylic acid 9 is a mono-activated moiety by virtue of a suitable leaving group Q which may be chloride, bromide, fluoride, N-hydroxysuccinimido, p-toluenesulfonyloxy or isobutyloxycarbonyloxy, but is not limited to these groups. After coupling, protecting group P4 is removed (if P4 is a benzyl group, hydrogenolysis over palladium-on-carbon (Pd-C) is performed) to give intermediate amino acid 7. 
Synthetic Scheme 3 describes the preparation of intermediate 8, a non-cyclic diamine. Many of the members of this class, such as ethylene diamine, N,N,Nxe2x80x2-trimethylethylene diamine, N,Nxe2x80x2-dimethylethylene diamine, N,Nxe2x80x2-dimethylpropylene diamine, etc. are commercially available starting materials. Other substituted diamines such as compounds 8a through 8c are obtainable by the procedures depicted in Scheme 3. For example, Boc-L-alanine methyl ester is reduced with diisobutylaluminum hydride to give the corresponding aldehyde which is then reductively aminated with methylamine, then the Boc group is cleaved to give 8a. Alternatively, the procedure of Miller, et al. J. Med. Chem. 19, 1382 (1976) may be employed to give intermediate 8. In another example, a suitably protected diamine is treated with trifluoroacetaldehyde in the presence of sodium cyanoborohydride to give an trifluoroethyl substituent on nitrogen, followed by deprotection to give amine 8.
Abbreviations used:
P1 is an N-protecting group; P2 is H or an oxygen protecting group; P3 is an N-protecting group; P4 is an oxygen protecting group such as benzyl or methyl; Q is a leaving group; Boc is t-butyloxycarbonyl; Cbz is carbobenzoxy.
The following Steps 1-13 constitute specific exemplification of methods to prepare starting materials and intermediates embraced by the foregoing generic synthetic schemes. Those skilled in the art will readily understand that known variations of the conditions and processes of the following preparative procedures can be used to prepare the compounds of Steps 1-13. All temperatures expressed are in degrees Centigrade.
Compounds of Examples 1-3 were prepared by using the procedures described in the following Steps 1-13:
Ozone/oxygen was bubbled at xe2x88x9270xc2x0 C. into a solution of (3S,4S)-N-[(tert-Butyloxy)carbonyl]-4-amino-3-acetoxy-5-phenylpentene (2.55 g, 8.0 mmol) (prepared by the method of Hanson, et al., J. Org. Chem. 50, 5399 (1985)) in 100 mL of methylene chloride until a deep blue color persisted. Oxygen was introduced until the blue color completely faded, then 3.0 mL of Me2S was added and the solution was allowed to warm to 0-5xc2x0 C. and stand overnight. The solvent was removed at 0xc2x0 C. under vacuum yielding the title compound as a thick yellow oil which was used in the following step without purification.
The oil prepared in Step 1 was dissolved under nitrogen in 100 mL of dry THF and cooled to xe2x88x9270xc2x0 C. To this solution was added 13 mL (26 mmol) of a 2.0 M solution of isobutylmagnesium chloride in ether and the stirred mixture was allowed to warm to room temperature and stir for 2 hrs. After decomposition with MeOH/H2O the mixture was diluted with ether, washed with saturated NH4Cl solution twice, then dried and the solvents stripped off under vacuum. The residue was allowed to stand overnight in 80% MeOHxe2x80x94H2O containing excess ammonium hydroxide. The MeOH was stripped off and the mixture was extracted with ether. These extracts were combined, washed with water, dilute KHSO4, then dried and evaporated to give 2.36 g of a yellow glass which crystallized from 50 mL of pentane on standing overnight. The yellow-white powder obtained was recrystallized from ether-hexane and furnished the title compound (0.41 g) as white, hairy needles, mp 134-136xc2x0 C., Rf (ether): single spot, 0.6. By chromatography of the mother liquors and crystallization of the appropriate fractions, an additional 0.22 g of product, mp 138-139xc2x0 C., was obtained.
Anal: Calcd. for C19H31NO4 (337.45): C, 67.62; H, 9.26; N, 4.15. Found: C, 67.51; H, 9.43; N, 4.24.
The diol of Step 2, 0.27 g, was reduced in MeOH with 60 psi H2 at 60xc2x0 C. in 3 hrs using 5% Rh/C catalyst. After filtering, the solvent was stripped off and the white crystals were recrystallized from CH2Cl2-hexane to furnish tiny needles of the title compound, 0.19 g, mp 126-128xc2x0 C.; further recrystallization gave mp 128.5-129.5xc2x0 C. Rf (ether): single spot, 0.8.
Anal: Calcd. for C19H37NO4 (343.50): C, 66.43; H, 10.86, N, 4.08. Found: C, 66.43; H, 11.01; N, 4.03.
The title compound of Step 3 (10 g) was dissolved 6.9N HCl in dioxane (300 mL). The mixture was stirred for 30 minutes at room temperature. The solvent was removed in vacuo and to the residue was added 5% aqueous sodium hydroxide (30 mL) until a pH of 14 was obtained. This mixture was extracted with ether and the ether extract was washed with water and brine, then the solvent was evaporated to give the title compound (7.3 g, 100% yield). 300 MHz 1H NMR: consistent with proposed structure.
Anal. calcd for C14H29NO2: C, 69.07; H, 12.01; N, 5.78. Found: C, 69.19; H, 12.34; N, 5.78.
D,L C-propargylglycine (10 g) was suspended in tetrahydrofuran (30 mL). Water (30 mL), potassium carbonate (36.7 g), and di-tert-butyl-dicarbonate (21.9 g) were added. Additional water was added to produce a solution which was stirred for 12 hours at room temperature. The organic solvent was then evaporated and the aqueous solution was washed with ether, then acidified to pH 3 with 1N aqueous citric acid. The solution was extracted with methylene chloride and the solvent evaporated to give the title compound (18.9 g, 97% yield), used without further purification.
D,L Boc-C-propargylglycine (1.2 g) was dissolved in methylene chloride (5 mL) and N-methyl piperidine (0.57 g) was added. The mixture was cooled to zero degrees centigrade and isobutyl chloroformate (0.78 g) was added. The mixture was stirred for 10 minutes whereupon the title compound of Step 4 (1.4 g) in methylene chloride (5 mL) was added and this mixture stirred for 15 minutes at 0xc2x0 C. and 4xc2x0 C. for 12 hours. The reaction mixture was washed successively with 1N citric acid, saturated sodium hydrogen carbonate, waster and brine. The organic layer was dried over magnesium sulfate and evaporated to dryness. 300 MHz 1H NMR: consistent with proposed structure.
The title compound of Step 6 (a 1:1 mixture of diastereomers) (0.76 g) was dissolved in a mixture of trifluoroacetic acid (4.9 mL) and methylene chloride (4.9 mL), and stirred for 30 minutes at room temperature. The solvent was then evaporated and the residue taken up in ethyl acetate. The organic layer was washed with saturated sodium hydrogen carbonate, water and brine, then dried over magnesium sulfate and evaporated. The residue was chromatographed on silica gel, eluting with ethanolchloroform-ammonium hydroxide (15:85:0.5). The faster running of the two diastereomers was collected and evaporated to give the pure title compound (0.2 g, 34% yield). 300 MHz 1H NMR: consistent with proposed structure.
Anal. calcd for C19H34N2O3: C, 67.4; H, 10.12; N, 8.31. Found: C, 66.6; H, 10.05; N, 8.02.
To a slurry of 4-(4-methoxybenzyl) itaconate (prepared by the method of Talley in U.S. Pat. No. 4,939,288) (50 g) in toluene (250 mL) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, 30.4 g) in one portion. Then a solution of benzyl bromide (34.2 g) in toluene (50 mL) was added dropwise over 0.5 hour. The reaction was stirred for 0.5 hour at room temperature and then poured into a separatory funnel. The mixture was washed with 3N HCl, aqueous sodium bicarbonate, brine and dried over magnesium sulfate. The solvent was evaporated to give a clear mobile liquid (68 g). Chromatography on silica gel, eluting with from 100% hexane to 25% ethyl acetate gave pure 1-(benzyl)-4-(4-methoxybenzyl) itaconate (55 g, 81% yield). A large Fisher-Porter bottle was charged with this itaconate (41 g), triethylamine (36 g), palladium acetate (380mg), tri-o-tolylphosphine (1.04 g) and iodobenzene (24.7 g). The bottle was sealed and flushed with nitrogen and placed in an oil bath and heated for 70 minutes. The residue was chromatographed on silica gel, eluting with 100% hexanes until the less polar impurities were removed. Eluting with 10% ethyl acetate in hexane gave the pure phenyl itaconate. This compound (23.8 g) was mixed with toluene (200 mL) and the resulting solution treated with trifluoroacetic acid (30 mL). The solution was stirred at room temperature for 1.5 hour and then evaporated. The residue was taken up in ether (150 mL) and treated with dicyclohexylamine (10.4 g) and stirred at 0xc2x0 C. whereupon the salt precipitated. This was isolated by filtration and washed with hexane and dried to give pure 1-benzyl 2-benzylidene succinoate dicyclohexylammonium salt (21.24 g, 78% yield). This benzylidene compound (20 g) was place in a Fisher-Porter bottle and also added were degassed methanol (200 mL) and rhodium (R,R)DiPAMP (600 mg) catalyst. The bottle was sealed and flushed with nitrogen then hydrogen. The reaction was hydrogenated at 40 psig for 15 hours at room temperature. The contents were then poured into a round bottom flask (500 mL) and the solvent evaporated to give a dark solid. The residue was taken up in boiling isooctane and allowed to stand, with some title compound crystallizing (7.34 g). The non-dissolved residue was taken up in boiling dimethoxyethane. This solution was allowed to cool for 12 hours, whereupon crystals of the title compound formed (6.05 g). Combining the two crops gave 13.39 g, 66% yield, mp 122-125xc2x0 C. 300 MHz 1H NMR: consistent with proposed structure.
The title compound of Step 8 (9.3 g) was suspended in a mixture of water (84 mL) and methanol (8.5 mL). Solid sodium bisulfate (6.12) was added and the mixture stirred for 5 minutes. The mixture was extracted with methylene chloride and the combined extracts were dried over magnesium sulfate and evaporated to dryness. The residue was chromatographed on silica gel, eluting with methanolchloroform-acetic acid (5:95:0.5), to give the pure title compound (4.3 g, 74% yield).
The title compound of Step 9 (4.3 g) was dissolved in methylene chloride (20 mL) and N-methyl piperidine (1.86 g) was added. The mixture was cooled to 0xc2x0 C. and isobutylchloroformate (1.97 g) was added. The mixture was stirred for 10 minutes whereupon N,N,Nxe2x80x2-trimethylethylene diamine (2.23 g) in methylene chloride (10 mL) was added. This mixture was stirred at 4xc2x0 C. for 3 hours, then washed with 1N citric acid, saturated aqueous sodium bicarbonate, water and brine. The solvent was evaporated to give the title compound (4.7 g, 85% yield). 300 MHz 1H NMR: consistent with proposed structure.
The title compound of Step 10 (4.6 g) was dissolved in ethanol (50 mL) and hydrogenated over 4% Pd-C at 5 psi at room temperature for 17 hours. The ethanol was evaporated to give the title compound (3 g, 71% yield). 300 MHz 1H NMR: consistent with proposed structure.
Benzyl L-3-phenyllactate (14.28 g) was dissolved in tetrahydrofuran (357 mL) and to this was added carbonyl diimidazole (9.78 g) and the mixture was stirred at room temperature for 4 hours. N,N,Nxe2x80x2-trimethylethylene diamine (6.8 g) was added and the mixture stirred for 8 hours. The solvent was evaporated and the residue taken up in ether and washed with water, dried over magnesium sulfate and evaporated to give a yellow oil (13 g, 61% yield); 300 MHz 1H NMR consistent with proposed structure. This ester was hydrogenated over 4% Pd-C @ 5 psi and room temperature for 3.5 hours in tetrahydrofuran. The title compound was obtained as a white solid (10 g) and recrystallized from methanol.
Anal. calcd for C15H22N2O4+H2O: C, 57.68; H, 7.75; N, 8.98. Found: C, 57.60; H, 7.82; N, 8.94.
The title compound of Step 6 (a 1:1 mixture of diastereomers) (2.3 g) was dissolved in a mixture of trifluoroacetic acid (14 mL) and methylene chloride (14 mL), and stirred for 30 minutes at room temperature. The solvent was then evaporated and the residue taken up in ethyl acetate. The organic layer was washed with saturated sodium hydrogen carbonate, water and brine, then dried over magnesium sulfate and evaporated to give the title compound as a mixture of diastereomers (1.8 g, 100% yield). 300 MHz 1H NMR: consistent with proposed structure.